"If all this sounds like some kind of gibberish, DD-WRT is
software that you can load ("flash") onto a compatible wireless
router, such as many models in the Linksys WRT54G family. The
DD-WRT software replaces the original ("stock") firmware included
by the manufacturer and provides many more features, some of which
are usually available in only expensive enterprise-grade routers,
such as bandwidth monitoring, hotspot management, client and bridge
modes, and output power adjustment.
"DD-WRT is not alone among alternative firmware projects.
Sveasoft, HyperWRT, OpenWRT, and Tomato all share a common family
lineage with DD-WRT that traces back to the original Linksys
firmware for its WRT54G V1 router. Because that firmware was
licensed as open source software under the GPL, developers
downloaded and built upon it. And in fact, DD-WRT is not the first
descendant of the original Linksys code to court controversy."